In the ice cream packaging industry, a variety of closure arrangements are used to hold a paperboard, plastic or composite lid in place on the paperboard container or tub holding the ice cream. An example of the combining of paper and plastic in the design of a container closure of this general kind is afforded by U.S. Pat. No. 6,053,353 (Helms), in which the composite lid includes a blank of sheet material and a peripheral molding, with a marginal portion of the blank being displaced out of the general plane of the central panel. The peripheral molding includes the marginal portion of the blank bonded to a portion of the rim on an exterior surface, in order to control longitudinal shrinkage and provide a printed surface on the marginal section.
In the composite lid of aforementioned U.S. Pat. No. 6,772,901, the top portion of the lid consists of a polymeric layer for moisture resistance attached to a paper disk suitable for the application of product identification printing on the top side. A poly-layer on the underside of the paper disk keeps moisture from the product from entering the paper and enables the disk to be bonded to the plastic ring. The top and bottom portions of the ring are bonded together by fusing the poly-layer of the paper to a landing on the plastic ring by conduction, ultrasonic or spin welding. Alternatively, a coating of adhesive applied to either surface before insertion of the disk may be used. Once joined together, the upper and lower portions form a composite-closure.